MMP9 released by glial cells may also contribute to the pathogenesis of ALS, leading to MN degeneration and muscle atrophy, resulting in alterations in the extracellular matrix [39] and a neurotoxic role for MMP9 has been already demonstrated using SOD1 and TDP-43 animal models for ALS [40, 41]. Here, MMP9 is linked to amyotrophic lateral sclerosis.